In cases where a patient has had ankle, knee, or hip surgery, it is sometimes necessary for a patient to gradually strengthen muscles, tendons, or ligaments associated with or located near those joints. Such muscles, tendons, or ligaments are often associated with maintaining balance, and they can often be strengthened by the use of a device that requires a user to balance himself.
In addition, there are various sporting activities and athletic endeavours that require balance, and a person may wish to improve his balance in order to improve his performance in such sporting activities and athletic endeavours. In such a case, a user may wish to train using a balancing device.
There are different types of balancing devices available. One is a “rocker”, consisting of a platform and an elongate balancing element. The user attempts to balance himself about the axis of the balancing element, and in doing so, usually produces a “rocking” motion.
Another example is early multi-directional balancing devices (often referred to as “wobblers”) that comprised a platform having an underside to which a semi-spherical balancing element is attached. The balancing element would be placed on the floor, and the user would stand on the opposite side of the platform, attempting to balance on the balancing element without allowing the platform to touch the ground, thus producing a “wobbling” motion. Such a device is shown in U.S. Pat. No. 3,024,021.
In a variant of such a design, the balancing element is supported against the bottom of the platform with springs, or other flexible elements. This is shown in FIG. 5 of U.S. Pat. No. 3,024,021. This can add an additional element of balancing for the user, because the user must not only balance his body about the balancing element to keep the platform from touching the ground; in addition, the balancing element itself is capable of angular displacement relative to the platform, and the user must keep his balance despite the angular displacement.
For both medical rehabilitation and physical fitness applications, it is desirable to gradually increase the difficulty of the balancing exercise, as the user's balance improves. Thus, in the wobbler sold by Fitterfirst of Calgary, Alberta, Canada, the balancing element is connected to the platform in a manner that permits angular displacement between the balancing element and the platform. This angular displacement is limited, and this limit is adjustable. The more angular displacement is permitted, the harder it is for a user to balance. To adjust the limit, the balancing element must be removed, and there are three discrete settings for the limit. To resume use of the device, the balancing element must be reattached.
One difficulty with this device is that the balancing element must be taken apart from the platform in order for the angular displacement limit to be adjusted. This causes adjustment of the wobbler to be time consuming and inefficient.